1. Technical Field
This invention relates to an engine hoist and, more particularly, to an engine hoist that is removably attachable to a trailer hitch and includes alternate lifting means.
2. Prior Art
The ability to use vehicles as a means for hauling objects as well as a means for transportation has always been a public concern. Consequently, various devices which mount to the rear of a vehicle to serve as a lift have been invented. One such device is disclosed in U.S. Pat. No. 2,867,402 issued on Jan. 6, 1959, to Graybill et al. Graybill et al. disclose an angled post with hooks at an upper end and a bumper clamp at the opposite end. The bumper clamp facilitates the mounting of the shaft to the rear bumper of a vehicle, while the hooks permit objects to be suspended for transportation by the vehicle.
U.S. Pat. No. 4,806,063 issued on Feb. 21, 1989, to York discloses a hoist which mounts to a ball trailer hitch. The hoist includes a multiple section boom which is provided with a winch. Straps attached to either side of a vehicle and a torsion bar mounted to the rear of the vehicle support the boom on the ball trailer hitch. The winch cable connects to a hanger which is used to support objects for transportation by the vehicle.
U.S. Pat. No. 5,064,078 issued on Nov. 12, 1991, to Van Staveren discloses a vehicle mounted crane. The crane includes a hydraulic cylinder to raise and lower its boom, and, further, mounts to a modified vehicle bumper using a specially designed support assembly. The distal end of the boom includes a chain which may connect to a variety of carrying devices such as a hook or an axle attachment-towing device.
U.S. Pat. No. 4,881,864 issued Nov. 21, 1989, to Amato discloses a hoist which attaches to a trailer hitch drawbar of a vehicle. The hoist includes a post connected to a tongue which fits within the trailer hitch drawbar to support the post. The lower end of the post includes an adjustable foot which aids in supporting the post. The post includes a boom which supports a cable driven by a winch attached to the post. The cable connects to a hook which is utilized to connect the cable to objects for hauling using the vehicle.
U.S. Pat. No. 5,211,526 issued on May 18, 1993, to Robinette discloses a mobile crane. The crane includes a central column which connects at a lower end to a T-shaped support and at its upper end to a boom. The T-shaped support fits within a trailer hitch drawbar to secure the crane to the rear of a vehicle. The crane further includes a hydraulic cylinder which vertically manipulates the boom.
Although the above-described devices operate adequately to lift objects for hauling, they each suffer from the disadvantage of difficult installation. For example, U.S. Pat. No. 2,867,402 uses a complicated clamping system to attach its post to the bumper of a vehicle, while U.S. Pat. No. 5,064,078 requires both a modified bumper and specially designed support assembly to mount its crane. Furthermore, both U.S. Pat. Nos. 4,806,063 and 5,211,526 require complicated and time-consuming assembly. Finally, U.S. Pat. No. 4,881,864 is difficult to mount into a trailer hitch drawbar because it is a single unit requiring strenuous exertion to be lifted and placed within the trailer hitch drawbar.
Accordingly, a hoist that requires little assembly and is extremely simple to mount to the rear of a vehicle is highly desirable.